The primary goal of these studies is to determine how the influenza virus proteins recognize each other during the assembly process that leads to the production of the infectious particles. This virus is found ubiquitously in nature, affecting man and animal and causing epidemics and pandemics of enormous proportions. The virus causes temporary debilitating illness with substantial economic losses to the business sector. Despite its importance in producing disease, its manner of replication and assembly are not entirely clear. This project deals with the major structural component of the virus, the membrane M1 protein with two main aims. The first deals with the phosphorylation of M1 and how the modification participates in or facilitates the distribution of M1 in subcellular compartments and at the site of assembly on plasma membranes. The second aim deals with ascertaining the existence of certain subviral particles (M1-RNP) in the cell which may progress to the plasma membrane site where budding occurs. These studies will involve the use of chemical cross-linkers, isolation of components by density gradients and immunoprecipitation of viral proteins. Temperature sensitive mutants will be used and assayed at restrictive and permissive conditions. Vaccinia recombinants containing the gene of M1 or M1 and NP will be used to determine the effect of phosphorylation of M1 on assembly and association of M1-RNP as the viral proteins proceed to the site of assembly.